You will see the word appassimento writ large on an increasing number of wine labels. It refers to wines made from grapes that have been dried for an extended period before being pressed and the juice fermented. The grapes lose water and therefore become sweeter and more concentrated in flavour. More sugar means more alcohol. It is a process that goes back many centuries, but until recently was confined to the Veneto region in north east Italy, and mainly in the production of one wine, Amarone.

In recent years, the practice has become popular the world over as a means of adding stuffing to wines that might otherwise be deemed a little too light or dilute.

The percentage of dried grapes can be varied giving more or less richness and power. Amarone can only be made in the Valpolicella region, so producers outside the region use the word appassimento instead.

Take a look at any Amarone producers’ website and you will see romantic images of grapes drying slowly on bamboo mats in ancient farmhouses. This is how the process was originally carried out. The reality for most wines is somewhat different. The grapes, when harvested, are laid out in plastic trays or on steel racks in air-conditioned, temperature-controlled drying rooms that are essentially industrial warehouses. We shouldn’t be too disappointed about this – in the past, the drying process was very haphazard with a constant danger that rot and other diseases would damage the grapes.

However, traditional producers are worried the larger co-operatives are now using inferior grapes and drying them for a shorter period, leading to cheaper but very mediocre Amarones.

There is a downside to drying grapes; as the grapes dry they lose volume – up to 30 per cent of potential volume. In addition to having greater alcohol and concentration, appassimento wines often have a slightly raisined flavour. The best wines have a wonderful complexity and can last for years.

In 1964, a member of the Masi family, one of the great producers of the Veneto, decided to experiment by fermenting his finished Valpolicella a second time on grape skins leftover from making the Amarone. This new wine had more fruit and alcohol. It became known as Ripasso, or re-passed, and has been an incredible commercial success over the past decade. Now many Valpolicellas are routinely made this way or made partly with dried grapes to increase body and mouth feel. Frustratingly it doesn’t always appear on the label; if like me you are a fan of lighter, fruity Valpolicella you have to look at the alcohol content – the ripasso method pushes it higher.

The concern regarding quality is not unfounded.

I recently tasted a very inexpensive appassimento made for the Scandinavian market. It had raisined fruit, lots of vanillin oak and very high levels of sugar. It tasted like the dregs of a cup of coffee had been added to some very cheap port. Not a pleasant experience, but apparently a popular way of keeping the northern winter at bay. You will find many cheaper wines on the Irish market – few live up to their promise.

For my tasting I received wines from Italy, Australia and Argentina. The proportion of dried fruit used varied from 20 to 100 per cent. Overall I noted two things; the best wines, including those below all had excellent length. I am not sure if this is a by-product of the appassimento and ripasso processes.

Secondly, you really do notice the extra alcohol; a number of the wines were 16.5 per cent. Having tasted 18 wines I was left feeling numb and a little dizzy.

The Veronese, with centuries of experience, have mastered the art of making appassimento wines. The great names, in addition to the producers below, include Zenato, Degani, Accordini, Corte Sant’Alda and Quintarelli. I still hanker for the more artisan side, light acidic Valpolicella and big earthy Amarones, but the more modern style sells far better.

Amarone has always been very popular in this country, especially with those who like rich turbo-charged wines. They can be drunk with food – robust stews (beef cheek or oxtail come to mind), game or risotto all’amarone.

I prefer it as a vino meditazione, or a wine to sip lowly after dinner, preferably with a few chunks of good Parmesan cheese. Sandro Boscaini of Masi agrees but proposes a few drops of honey alongside the Parmesan. jwilson@irishtimes.com